Sean –
I agree. I have very few plugins installed on that site. I have a plugin that runs daily and weekly backups. The daily backups aren’t full (in that I’m not backing up the full site – maybe I should be). The weekly backups are full. In any case, I don’t think a plugin itself caused the login errors. I think those somehow got caused when I removed the bbPress plugin. No idea how. All I know is that after I removed bbPress, that’s when the trouble began.